Week 4 Sarcoma

Question 1

Sarcoma general info

Answer 1

Peak in young and over 60
46% extremities
Grow longitudinally and compress radially
Rare to mets to LNs
Most met direct extension or to lungs

Question 2

Sarcoma tx options

Answer 2

Limb salvage-Surgery has min. 1 cm margin-tumors stay mostly encapsulated but can seed
Amputation

Question 3

Limb salvage radiation preop

Answer 3

clear tumor definition, potential for reduction in seeding, sterilizes tumor, clearer margins
Higher wound complications, challenges with healing post op
50Gy in 2Gy per fraction, 3 weeks recover prior to resection, Can be modified with chemoradiation protocol (1.8Gy)

Question 4

Limb salvage XRT post op

Answer 4

evaluation of entire surgical margins
higher late related wound complications=fibrosis, joint stiffness, edema
50Gy plus/minus 16Gy boost for positive margins to post op bed.

Question 5

General XRT sarcoma guidelines

Answer 5

positioning: minimize soft tissue distortion, frog leg for upper thighs, bolus on incisions (in sim is helpful for planning)
Margins: 5-10 cm longitudinally, 2-3 cm radially
IMRT: need MRI, 3 cm longitudinally 1.5 cm radially

Question 6

Sarcoma IMRT considerations

Answer 6

Bone sparing, reduce dose to soft tissue, special care of dose to skin flaps,
Concerns: skin dose harder to get, hotspots more inhomogeneous, more low dose radiation– concerns for edema and secondary malignancy

Question 7

Bone sarcomas

Answer 7

Uncommon, chemo is critical, surgery is preferred tx, radiation helpful in improving local control of unfavorable sites–pelvis, sacrum, spine, and craniofacial

Question 8

Ewing sarcoma

Answer 8

Radiosensitive

55.8Gy+chemo